Electric fan and motor therefor and for other purposes.



G. S. TIFFANY. ELECTRIC FAN AND MOTOR THEREFOR AND FOR OTHER PURPOSES.APPLICATION FILED OCT. 9. 1911.

1,212,282. Patented Jan. 16,1917.

2 SHEETS-SHEET I.

, RUG/(Z107? G. S. TIFFANY.

ELECTRIC FAN AND MOTOR THEREFOR AND FoR OTHER PURPOSES.

APPL ICATI 0 N F I LE D OCT. 9. I 9 1 I 1,212,282. Patented Jan.16,1917.

2 SHEETS-S HEET 2.

m lllllllllll d UNITED STATES PATENT OFFICE.

GEORGE S. TIFFANY, OF SUMMIT, NEW JERSEY, ASSIGNOR T0 GRAY ELECTRICCOMPANY, OF NEW YORK, N. Y.. A CORPORATION OF ILLINOIS.

Specification of Letters Patent.

Patented Jan. 16, 1917.

Application filed October 9, 1911. Serial No. 653,510.

To all whom it may concern:

Be it known that I, GEORGE S. TIFFANY, a citizen of the United States,residing at Summit, county of Sussex, and State of New Jersey, haveinvented certain new and useful Improvements in Electric Fans and MotorsTherefor and for other Purposes, fully described and represented in thefollowing specification and the accompanying drawings, forming a part ofthe same.

This invention relates, to improvements in electric motors for operatingfans and for other purposes; the principal object of the presentimprovements being to provide a motor which is self starting on theclosing of the circuit including it; in which the speed may be varied atwill, economically, with respect to the consumption of current; and inwhich sparking at the brush contacts will be effectively eliminated.

As a full understanding of the improvements constituting the presentinvention can best be had from a detailed description of an organizationembodying the same, such description will now be given in connectionwith the accompanying drawings, in which- Figure 1 is a front elevationof a fan and motor therefor embodying the present improvements. Fig. 2is a side elevation of the same, looking toward theleft of Fig. 1. Fig.3 is a rear view of the same looking toward the left of Fig. 2, showingthe motor. Fig. 4 is a vertical sectional elevation of the motor, on anenlarged scale. Fig. 5 is a vertical section'on the line 5 of Fig. 4.Fig. 6 is a horizontal section on the line 6 of Figs. 4 and 5; and Figs.7 and 8 are diagrammatic views illustrating the electric circuit for themotor.

Referring to said drawings the motor will first be described. The magnet1 of the motor is constructed preferably of soft steel laminationshaving a magnetizing winding 2; said laminations being clamped togetherby yokes 3, 4, provided with bolts 5, passing therethrough and throughsuitable openings in said laminations. The rotary armature 6 of themotor is of approximately 8 shape, conforming peripherally to the areshape of the opposed poles of the magnet. This armature 6, which is alsopreferably formed of soft steel laminations, is fixed to a shaft 7rotating in a bearing 8 fixed to or forming part of the yoke 3; thisbearing and yoke 3 being so positioned as to support the shaft 7 andarmature 6 in proper relation to the poles of the magnet 1. Shaft 7 andarma ture 6 also carry a commutator consisting of two are shaped metalplates 9, 10, secured to a disk 11 of insulating material, which is, inturn, secured by a screw 1.2 to the inner end of shaft 7, as best shown1n Figs. 4, 6. The metal plates 9, 10, of the commutator rotate withshaft 7 and armature 6, and as so rotated, are engaged by a pair ofbrushes 13, 14, connected, as shown in Figs. 7 and 8, with a source 15of electric energy, such connections consistmg of wires 16, 17, winding2 of magnet 1, wire 18, contact brush 13, plate 9 (or 10, according tothe position of the commutator), contact brush 14, wire 19, and wire 20to the source 15 of electric energy.

Bru sh 13, which is preferably of woven w1re, 1s suitably mounted in atube 21 of insulating material, secured in a suitable open- 1ng 1n yoke4, and it is held yieldingly in engagement with the commutator by aspring 22 in said tube in rear of said contact brush, a metal washer 23connected with said spring (and to which circuit wire 18 is connected)and a screw plug of insulating material which is threaded in the outerend of the tube 21. Contact brush 14, which, however, is preferably ofgraphite, is also contained in a tube 24 of insulating material, and isheld yieldingly in engagement with the commutator by means of a spring25, metal washer 26 connected therewith, and to which circuit wire 19 isconnected, and a screw threaded plug 27 of insulating material in theouter end of said tube 24. Contact brush 14, however, is adjustable toand from contact brush 13, and to provide for this adjustment the tube24 containing this contact brush is mounted in an arm 28 which, in turn,is pivotally mounted on a stud 29 secured to the yoke 4,. in axialalinement with shaft 7, so that said arm 28 may be swung concentricallyto said shaft and its contact brush 14, thereby adjusting it to and fromcontact brush 13 in the path of movement of the commutator plates 9, 10.Contact brush 14 and the arm 28 in which it is mounted also constitutethe circuit controlling means by which the motor circuit is opened andclosed to start and stop the motor, and also to regulate its speed; thecif-- cuit being opened by moving contact brush and the circuit beingclosed by moving said brush 14 into contact with the commutator plate 9or 10, as the case may be, with which brush 13 may at the time be incontact; the speed of the motor being also regulated by moving the brush14 to and from brush 13. Upon the movement ofthe arm 28 to the positionin which it is shown in Figs. 3 and 4, the circuit from the source 15 ofelectric energy will be closed through magnet 1, and the latter thus. beenergized, with the result that the armature 6 and the commutator willbe rotated in a counterclockwise direction. As the armature 6 is thusrotated, the commutator plate 9 will move out of contact with brush 13,thus breaking the motor circuit at this point. The momentum of thearmature 6, however, will cause it to continue to rotate and thus bringcommutator plate 10 into engagement first with contact brush 13, andthen with contact brush 14, which then again closes the circuit,reestablishing the motor circuit and energizing the magnet 1, which willact upon armature 6 to give it additional impetus, causing it toaccelerate its speed, and so on.

To relieve the insulation of the motor from the strain resulting fromthe current discharges of the winding 2 of magnet 1, a high resistanceshunt 31 is bridged around the winding 2, as shown in Figs. 7 and 8.

In motors as heretofore constructed, when contactbetween the brush 13and the commutator plates 9 and 10 is broken, sparking results, whichis, of course, objectionable for reasons that need not be stated. Thissparking is avoided in the present case by the provision of a condenser32 bridged across the contacts 13, 14, between the wires 19, 19, asshown in Figs. 7 and 8, which condenser momentarily offers a path. forthe current immediately after the circuit is thus broken.

I prefer graphite for the contact brush 14 and metal for the contactbrush 13 for the reason that by the use of a graphite brush for closingthe circuit, and a metal brush for breaking the circuit, there is lesstendency for the discharge from the condenser 32 to injure thecommutator plates 9, 10, with such an arrangement of contact brushesthan otherwise, and, furthermore, the graphite also acts as a lubricant.

The object in providing for the relative movement above referred to ofthe commutator brushes 13, 14, or, in other words, the ad ustment ofcommutator brush 14 to and from commutator brush 13, is not only to stopand start the motor but also, as before indicated, to vary, as desired,the duration of the current impulses passing through the motor circuitsfrom the source of electric energy 15, the duration of such currentimpulses being increased'as the brush 14 is ad I shown in Fig. 7 to theposition in which it is shown in Fig. 8, the duration of such currentimpulses will be shortened, as in such case a short angular movement ofthe commutator 6 will cause the plate 9 to pass out of contact with thebrush 13. This shortening of the current impulses will cause adiminution of the mean strength of the currents passing through themotor circuits, and will consequently slow down the motor. This methodof varying the speed is. much more economical of current consumptionthan the usual method of interposing more or less resistance into thecircuit, as in the present method all of the current isv consumed in themotor, while in the other method more or less current is wastedin theexternal resistance. Shaft 7 is also provided with an overbalancingdevice, the purpose of which is, when the motor slows down in stopping,to cause the armature 6 to stop in such a position with relation to thepoles of the magnet 1 that when said magnet is again energized by theclosing of the motor circuit, said armature will at once begin to rotatein the right direction, as will presently more fully appear. Thespecific form of device provided for this purpose by the presentinvention, and which embodies this feature of the invention in itspreferred form, consists of a tube 33 secured to the out-er end of shaft7 by means of a pin 34 passing through the middle of the tube 33; thispin also securing to the shaft a plug 35 of suitable material, tightlyfitting said tube so as to divide it into two chambers 36, 37, of equallength, the outer end of each chamber 36, 37 being also sealed by a plug38. Each of the chambers 36, 37 is supplied with a quantity of mobilematerial 39, preferably mercury, the amount in each being the same.Normally, the tube 33 will occupy the perpendicular position in which itis shown in Fig. 3; the mercury in chamber 36 or 37 as the case may be,because of its location in the lower end thereof, overbalancing themercury in the other chamber, and thereby causing the armature 6 toassume the position in which it is shown, in which position, it will beobserved, the points of the armature are in a position to be attractedmore strongly by the poles of the magnet 1 than are the fiat backs ofthe armature, so that, immediately upon the closing of the motor circuitby the movement of contact 14, as before described, the armature willbegin to rotate in the direction of the arrow, Fig. 2. As it rotates,the mercury in the chamber 36 or 37 (whichever happens to be uppermostat the time of starting) will,

because of the centrifugal force set up by said chamber, and thusoverbalance the mercury in the uppermost chamber and cause the armature6 to again assume the position in which it is illustrated in Figs. 2

and 3.

Another valuable feature of the motor above described, in addition tothose heretofore referred to, is that it will operate efliciently uponalternating current, as there are no windings on the armature to set upcomplex phase relations in the currents.

The motor shaft 7 has fixed to its front end by set screw 40 (see Fig.4) a fan 41, which is inclosed by a suitable wire guard or cage 42 ofsimple, cheap, and at the same time durable construction. This guard orcage consists of a pair of central tubular rings 43, 44, on oppositesides of the fan 41; a series of spring wires 45, connected at theirends with rings 43, 44, and suitably' bowed lengthwise, as shown inFigs. 1 and 2, to inclose the blades of the fan; and a strengtheningwire ring 46 sprung into re cesses 47 formed in the wires midway oftheir lengths (see Fig. 2). The wires 45 are connected with the tubularrings 43, 44,

by means of plugs 48 of solder in the rings (Fig. 1), in which the endsof the wires 45, passed through suitable peripheral openings in therings, are embedded. The guard or cage is connected with the motor framethrough the ring 44, which, aswill be observed, on reference to Fig. 4,rests, at its upper portion, in a suitable recess formed in the bearing8 of the frame, and is secured to the frame by screws 49 (Figs. 1 and4). The wires 45 instead of extending in radial lines from the rings 43,44, extend in lines tangential thereto or, in other words, are bent awayfrom radial position. This gives them a certain amount of resiliency sothat they will firmly grip the stiffening ring 46 sprung into therecesses 47, thus rendering it unnecessary to secure them to wire 46, asby solder; a very rigid guard being. thus secured and. one which islight and durable and also cheap to manufacture, both ,in cost ofmaterials and labor. i

The fan and motor are adjustably mounted on a pedestal 50through whichthe circuit connections from the source 15 of electric energy may bepassed. The adjustable connection of the fan and motor is secured byproviding pedestal 50 with an upwardly extending yoke shaped bracket 51,in which the motor is pivotally mounted, as at 52,

bracket 51 being provided with an opening and a pin 53 passingtherethrough and any one of a set of openings in the magnet heads 54according to the inclination to which the fan and motor may be adjusted.

What I claim is 1. The combination with an electric motor and circuitcontrolling means for alternately making. and breaking the motor circuitas the motor operates, of spark-annuling means affording a path for theextra current as the motor circuit is thus broken, a circuit controllingmeans for alternately making and breaking the motor circuit as the motoroperates, comprising a circuitclosing contact of carbon and a circuitbreaker of metal, substantially as described.

- 2. The combination with an electric motor, of a circuit interrupterhaving a circuit closing contact and a separate circuit breakingcontact, for making and breaking the motor circuit, means for annulingthe spark at the breaking of the circuit by said interrupter, and meansfor varying the relative duration of the open and closed circuit periodsof the motor circuits by varying the relative positions of said circuitclosing contact and said circuit breaking contact.

3. The combination with an electric motor, of circuit controlling meansfor alternately making and breaking the motor circuit as the motoroperates, comprising a circuit closing contact and a circuit breakingcontact one adjustable relatively to the other to vary the time ofcontact controlling the interrupted currents for operating said motorand thus varying the speed of the motor, substantially as described.

4. The combination with an electric 1110-.

the time of contact controlling the interrupted currents for operatingsaid motor and thus varying the speed of the motor, substantially asdescribed. 5. The combination with an electric motor and its rotatingarmature of means including a centrifugally movable weight forautomatically positioning the .armature in an unbalanced magneticrelation to the magnet as the motor circuit is broken'and the armaturecomes to rest, whereby the motor becomes self starting on the closing ofthe circuit.

6. The combination with :an electric motor and its rotating armature, ofmeans for automatically positioning the latter in an unbalanced magneticrelation to the magnet as the motor circuit is broken and the arma- Intestirnony whereof, have hereunto set my hand, in the presence of twosubscribing 1 0 witnesses.

GEORGE S. TIFFANY.

Witnesses:

1. WHITE, S. E. BROWN.

